The field of the invention is building materials and the invention relates more particularly to sealing materials typically used in weatherproofing a structure. Metallic roof flashings typically made from aluminum or other deformable metal have been used for many years to provide a weatherproof joint between a roof and a parapet or at the intersection of different roofing surfaces. Such flashing materials typically form the most vulnerable portion of a roof, and water leaks at such joints are common. Improved materials have recently been made available which permit improved roofing surfaces, and the use of a membrane or a single ply roofing material made from an elastomeric sheet provides a high degree of weatherability as compared to the older style of asphalt built-up roof. In spite of the improvement in roofing materials, the problem of sealing adjacent surfaces remained and a better way to weatherproof such joints is needed.
Another common sealing problem comprises expansion joints in large surfaces which often are filled with a flexible sealant which is expected to deform to follow the opening and closing at the expansion joint. Such sealants, typically, are not capable of providing satisfactory sealing characteristics against the possibility of the leakage of water.